JP2820952B2 - Liquid polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a liquid polymer which is excellent in operability and gives a polyurethane having excellent heat resistance, weather resistance, water resistance, adhesiveness and rubber elasticity. Related to the composition contained.

[Conventional technology]

2. Description of the Related Art Conventionally, polyurethanes made of polyester-based and polyether-based polyols have been widely used for various sealing materials, coating materials, potting materials, and the like. However, conventional polyurethanes composed of polyester-based and polyether-based polyols have problems in water resistance, hydrolysis resistance, heat resistance, weather resistance, etc. due to ester bonds and ether bonds present in the molecular chains. In recent years, polybutadiene-based polyols have come to be used, but these have improved water resistance and hydrolysis resistance, but they have heat resistance and weather resistance due to the unsaturated bonds present in the molecular chains. Inferior. In order to improve the heat resistance and weather resistance, a method of hydrogenating unsaturated bonds in the molecular chain has been adopted.In the case of polybutadiene-based polyol, the structure of the main chain becomes a polyethylene structure by hydrogenation, and In order to show the property, it becomes a solid at normal temperature and the operability decreases significantly.
Further, the obtained polyurethane has disadvantages such as not exhibiting good rubber elasticity.

[Problems to be Solved by the Invention] The present invention provides a polyurethane having excellent water resistance, hydrolysis resistance, heat resistance, and weather resistance and having good adhesiveness, and mixing and molding when obtaining the polyurethane. It is an object of the present invention to provide a composition containing a polyol for polyurethane, which is excellent in operability of polyurethane.

[Means for solving the problem]

The present inventors have found that a partially hydrogenated liquid polymer having an unsaturated bond in the range of 78 to 85% of a liquid isoprene polymer having a hydroxyl group is suitable as a polyol for polyurethane. completed.

That is, the present invention relates to a liquid polymer obtained by hydrogenating a liquid isoprene polymer having a number average molecular weight of 700 to 7,000 and having 1.5 to 5.0 hydroxyl groups in one molecule in an unsaturated bond range of 78 to 85%. And a composition containing an organic polyisocyanate compound.

The hydroxyl group-containing liquid isoprene polymer used in the present invention needs to have a number average molecular weight in the range of 700 to 7,000. When the number average molecular weight is less than 700, the polyurethane obtained using the hydrogenated product does not have good rubber elasticity. On the other hand, when the number average molecular weight exceeds 70,000, the hydroxyl group-containing liquid isoprene polymer and its hydrogenated product do not show good fluidity, and the operability in producing the polyurethane is unpreferably deteriorated. From this point of view, the number average molecular weight needs to be in the above range, especially
Preferably it is between 1,000 and 5,000.

The hydroxyl group-containing liquid isoprene polymer has a molecular weight of 1.5%.
It is necessary to have ~ 5.0 hydroxyl groups. When the number of hydroxyl groups in one molecule is less than 1.5, sufficient crosslinking cannot be performed in a polyurethane using the partially hydrogenated product, and the strength properties become insufficient. Also, 5.0
If it exceeds, the crosslink density becomes too high and a polyurethane exhibiting good rubber elasticity cannot be obtained. Therefore, the number of hydroxyl groups per molecule needs to be within the above range, especially 1.
It is preferably between 8 and 3.0. The hydroxyl group may be at the terminal of the molecular chain or in the chain, but is preferably at the terminal.

Such a hydroxyl group-containing liquid isoprene polymer can be obtained by a known method. For example, an isoprene monomer is converted to hydrogen peroxide or an azo compound having a hydroxyl group (for example, 2,2
2′-azobis [2-methyl-N- (2-hydroxyethyl) -propionamide] or the like or a peroxide having a hydroxyl group (for example, cyclohexanone peroxide or the like) as a polymerization initiator, and 0.1 to 40 with respect to the isoprene monomer. A hydroxyl group-containing liquid isoprene polymer can be obtained by using it in the range of mol% and performing radical polymerization.
Also, 100 parts by weight of isoprene monomer is used as a polymerization initiator such as naphthalenedilithium and dilithiohexylbenzene, and 0.1 to 5 parts by weight of isoprene monomer is used.
After the anionic polymerization, 1 to 300 mol of ethylene oxide, propylene oxide or the like is added to 1 mol of the polymerization initiator to obtain a hydroxyl group-containing liquid isoprene polymer.

In both cases of radical polymerization and anionic polymerization, it is necessary to use a solvent inert to the catalyst. Examples of the solvent in the case of radical polymerization include alcohols such as ethanol and propanol, aliphatic and alicyclic hydrocarbons such as hexane, heptane and cyclohexane, and aromatic hydrocarbons such as benzene and toluene. Examples of the solvent in the case of anionic polymerization include aliphatic and alicyclic hydrocarbons such as pentane and cyclohexane, and aromatic hydrocarbons such as benzene and toluene.

The amount of the solvent can be arbitrarily determined, but is desirably 80% or less of the entire polymerization system. The conditions for carrying out the polymerization are not particularly limited.
The reaction is performed at a reaction temperature of 200 ° C. and a reaction time of about 1 to 100 hours.

A liquid isoprene polymer containing a hydroxyl group in the terminal or in the molecular chain can be obtained by the above-described method, and as another method for obtaining a liquid isoprene polymer containing a hydroxyl group in the molecular chain, a liquid isoprene containing no hydroxyl group is used. There is a method in which a polymer is obtained by radical polymerization or anionic polymerization, and thereafter, a hydroxyl group is introduced by, for example, a method disclosed in JP-A-57-16003.

In the present invention, the hydroxyl group-containing liquid isoprene polymer is used after hydrogenation. At this time, it is necessary to hydrogenate 78 to 85% of the unsaturated bonds in the polymer.

The liquid isoprene polymer having a hydroxyl group has excellent adhesiveness due to an isoprene skeleton having an unsaturated bond while the heat resistance and weather resistance are reduced due to the unsaturated bond, but the hydrogenation rate is in the above range. By using the isoprene polymer described in (1), it is possible to obtain a polyurethane having improved heat resistance and weather resistance while utilizing excellent adhesiveness.

Hydrogenation of the hydroxyl group-containing liquid isoprene polymer can be performed using a known method. For example, a method of performing catalytic hydrogenation using a Ziegler-based homogeneous catalyst or a solid heterogeneous catalyst is employed.

When a homogeneous catalyst is used, a saturated hydrocarbon such as hexane or cyclohexane or an aromatic hydrocarbon such as benzene, toluene, or xylene is used as a solvent at a reaction temperature of room temperature to 200 ° C. and a hydrogen pressure of normal pressure to 100 kg / cm ² . The hydrogenation reaction takes place under pressure. As the homogeneous catalyst, a Ziegler catalyst or the like obtained by combining a transition metal halide with an alkylated product such as aluminum, alkaline earth metal or alkali metal is used in an amount of about 0.01 to 0.1 mol% based on the unsaturated bond of the polymer. Ends in ~ 24 hours.

When a heterogeneous catalyst is used, saturated hydrocarbons such as hexane and cyclohexane, aromatic hydrocarbons such as benzene, toluene, and xylene, ethers such as diethyl ether, THF, and dioxane; alcohols such as ethanol and isopropanol; The hydrogenation reaction is carried out at a reaction temperature of normal temperature to 200 ° C. under a hydrogen pressure of normal pressure to 100 kg / cm ^{2 using} a mixed system of as a solvent. As the heterogeneous catalyst, use a metal such as nickel, palladium, ruthenium, and platinum alone or on a carrier such as silica, diatomaceous earth, alumina, or activated carbon, and use about 0.5 to 10% based on the weight of the polymer. The reaction is usually completed in 1 to 48 hours.

The composition of the present invention comprises the hydrogenated polymer and 2 per molecule.
It comprises an organic polyisocyanate compound having at least two isocyanate groups.

As the organic polyisocyanate compound used here, those having two isocyanate groups in one molecule include, for example, tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate. And those having three or more isocyanate groups in one molecule include, for example, triphenylmethane triisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, polymethylene polyphenyl polyisocyanate and the like. This composition is used in various applications as polyurethane by crosslinking and curing. As a curing method of this composition, a method of mixing a hydrogenated product of a hydroxyl group-containing liquid isoprene polymer and an organic polyisocyanate compound, heating and mixing in some places, and curing (one-shot method), a method of curing a hydroxyl group-containing liquid isoprene polymer, A method of preliminarily reacting the hydrogenated product of the coalescence with the isocyanate group of the organic polyisocyanate compound to obtain a hydrogenated product of a liquid isoprene polymer having an isocyanate group, and curing this using a curing agent (prepolymer method), etc. Can be The amount of the organic polyisocyanate compound used is 1 to 50 parts by weight based on 100 parts by weight of the hydrogenated product of the hydroxyl group-containing liquid isoprene polymer.

In the case of the one-shot method, the ratio of the hydroxyl group (OH) in the hydrogenated product of the hydroxyl group-containing liquid isoprene polymer to the isocyanate group (NCO) in the organic polyisocyanate compound is as follows:
The molar ratio NCO / OH is in the range of 0.5 to 5.0. This ratio is 0.
If less than 5, the resulting polyurethane does not have sufficient strength. When the ratio exceeds 5.0, the obtained polyurethane does not have sufficient rubber elasticity.

When the composition of the present invention is cured, a chain extender for a polyol or a polyamine compound, or a plasticizer such as a higher alcohol or dioctyl phthalate may be used in addition to the organic polyisocyanate compound. There is no particular limitation on the amount of the chain extender or the plasticizer, but the chain extender is 1 to 2 per 100 parts by weight of the hydrogenated liquid isoprene polymer hydrogenated product.
In the range of 50 parts by weight, the plasticizer is used in the range of 1 to 500 parts by weight.

On the other hand, in the case of the prepolymer method, the molar ratio of the hydroxyl group (OH) in the hydrogenated product of the hydroxyl group-containing liquid isoprene polymer to the isocyanate group (NCO) in the organic polyisocyanate compound is NCO / OH = 2.0 to 5.0. Is within the range. If this ratio is smaller than 2.0, problems such as a significant increase in viscosity during the reaction are not preferred. When this ratio exceeds 5.0, the obtained polyurethane loses rubber elasticity. The reaction temperature in the first half of the prepolymer method is from room temperature to
The reaction is performed at 150 ° C. for a reaction time in the range of 0.1 to 20 hours. At this time, a compound such as tin or lead can be used as a catalyst. A hydrogenated product of a liquid isoprene polymer having an isocyanate group obtained by a prepolymer method is crosslinked and cured using water, a polyol compound and a polyamine compound. When these are used as a cross-linking agent, the molar ratio (OH or NH ₂ / NCO) of a hydroxyl group or an amino group to an isocyanate group is used in a range of 0.5 to 5.0.

Here, in both the prepolymer method and the one-shot method, the polyol compound is ethylene glycol,
Propylene glycol, butanediol, pentanediol and the like are used, and as polyamine compounds, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenyl and the like are used. In addition, in any of the one-shot method and the prepolymer method, various compounding agents used when producing ordinary polyurethane can be added. For example, carbon black, silica,
Reinforcing agents, fillers, phenols, such as calcium carbonate,
Examples include amine-based anti-aging agents, rosin-based and terpene-based tackifier resins, naphthene-based, paraffin-based, and aroma-based process oils, and plasticizers such as dioctyl phthalate and dioctyl adipate. The use amount of these is not particularly limited as long as the purpose and effect of the present invention are not impaired, and is appropriately determined.However, a reinforcing agent is usually used for 100 parts by weight of a hydrogenated product of a hydroxyl group-containing liquid isoprene polymer. , Filler is 0 to 500 parts by weight, antioxidant is 0
It is appropriate to use 0 to 10 parts by weight, 0 to 300 parts by weight of the tackifier resin, and 0 to 500 parts by weight of the plasticizer.

Regarding the conditions for curing, in both the prepolymer method and the one-shot method, the reaction temperature is generally room temperature to 200 ° C., preferably 60 to 150 ° C., and the reaction time is generally 0.1 to 20 hours.

The polyurethane obtained by using the composition of the present invention has excellent water resistance, hydrolysis resistance, heat resistance, and weather resistance, and has good adhesiveness and sufficient strength properties. It can be suitably used for the intended use. For example,
Examples include a pressure-sensitive adhesive, a sealing material, a coating material, a coating film waterproof material, a waterproof sheet, an electric component sealing material, and a material for automobiles.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded.

Example 1 In a 1-liter autoclave, isoprene was polymerized using an anionic polymerization initiation catalyst composed of a naphthalene / sodium system, and then a hydroxyl group-containing liquid isoprene polymer (Mn = 4,500, obtained by adding ethylene oxide and then water). OH value = 23.6mgKOH / g) 100g, Raney nickel 10g (nickel content 50%), and heptane 200g as a reaction solvent were charged, and the inside of the system was replaced with purified nitrogen gas. The temperature rose. 200
When the temperature reached a steady state at a temperature of ° C., high-purity hydrogen gas was supplied to the autoclave, and a hydrogenation reaction was performed while maintaining the internal pressure of the system at 50 kg / cm ² . After the reaction, the hydrogenated product was taken out, the catalyst was removed by filtration, and the solvent was distilled off to obtain a hydrogenated product (I).
The hydrogenation rate of the hydrogenated product (I) was 78% as a result of an iodine value measurement. Table 1 shows the formulation of the hydrogenated product (I) and the organic polyisocyanate compound and the physical properties of the obtained polyurethane.

In Table 1, the high elongation was measured according to JIS-K6301. The adhesive strength was evaluated by applying a 5 mm thickness to a degreased steel sheet, curing the applied steel sheet, and measuring a 90 ° peel stress. Further, in the heat resistance test, the cured product was heated in a gear oven at 120 ° C. for one week, and a change in the state was examined.

Example 2 A hydrogenated product (II) was obtained in the same manner as in Example 1 except that the reaction time was slightly longer than that in Example 1. Hydrogenated product (II)
Was 83% as a result of iodine value measurement. Table 1 shows the formulation of the hydrogenated product (II) and the organic polyisocyanate compound and the physical properties of the obtained polyurethane.

Comparative Example 1 In a 1-liter autoclave, 100 g of a hydroxyl-containing liquid isoprene polymer (Mn = 2,600, OH value = 45.3 mgKOH / g) obtained by radical polymerization using hydrogen peroxide, and 10 g of reduced nickel (35% nickel loading) , Carrier: diatomaceous earth) and 200 g of cyclohexane as a reaction solvent, and the inside of the system was purged with purified nitrogen gas, and then heated to 150 ° C. over 30 minutes. When a steady state at 150 ° C. was reached, high-purity hydrogen gas was supplied to the autoclave, and a hydrogenation reaction was performed while maintaining the internal pressure of the system at 50 kg / cm ² . After the reaction, the hydrogenated product was taken out, the catalyst was removed by filtration, the solvent was distilled off, and the hydrogenated product of the hydroxyl-containing liquid isoprene polymer (II
I got. The hydrogenation rate of the hydrogenated product (III) was 64% as a result of an iodine value measurement. Table 1 shows the formulation of the hydrogenated product (III) and the organic polyisocyanate compound and the physical properties of the obtained polyurethane.

Comparative Example 2 A hydrogenated product (IV) was obtained in the same manner as in Comparative Example 1 except that the hydrogenation reaction was completed in a shorter time than in Comparative Example 1. Hydrogenated product (I
The hydrogenation rate of V) was 52% as a result of an iodine value measurement. Table 1 shows the formulation of the hydrogenated product (IV) and the organic polyisocyanate compound and the physical properties of the obtained polyurethane.

Comparative Example 3 A hydrogenated product (V) was obtained in the same manner as in Comparative Example 1, except that the reaction temperature was 135 ° C. and the hydrogenation reaction was completed in a short time as compared with Comparative Example 1. The hydrogenation rate of the hydrogenated product (V) was 32% as a result of an iodine value measurement. Table 1 shows the formulation of the hydrogenated product (V) and the organic polyisocyanate compound and the physical properties of the obtained polyurethane.

As shown in Table 1, the polyurethane obtained from the hydrogenated product (V) of the hydroxyl group-containing liquid isoprene polymer having a low degree of hydrogenation has good adhesiveness to a steel sheet, but has extremely poor heat resistance. I understand.

Comparative Example 4 A hydrogenated product (VI) was obtained in the same manner as in Comparative Example 1 except that 15 g of reduced nickel was used. The hydrogenation rate of the hydrogenated product (VI) was 97% as a result of an iodine value measurement. Table 1 shows the formulation of the hydrogenated product (VI) and the organic polyisocyanate compound and the physical properties of the obtained polyurethane.

As shown in Table 1, it can be seen that the polyurethane obtained from the hydrogenated product (VI) of the hydroxyl group-containing liquid isoprene polymer having a high degree of hydrogenation has excellent heat resistance but poor adhesion.

[Effect of the Invention] The liquid polymer composition of the present invention can be produced without any operational difficulties, and has excellent water resistance, hydrolysis resistance, heat resistance, weather resistance, and good water resistance. Gives polyurethanes with adhesive, sufficient strength properties.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08G 18/69 C09D 175/14 C09J 175/14

Claims (1)

(57) [Claims] 1. A liquid polymer having a number average molecular weight of from 700 to 7,000 and a hydrogenated isoprene polymer having 1.5 to 5.0 hydroxyl groups in one molecule, wherein the unsaturated bond is hydrogenated in the range of 78 to 85%. And a liquid polymer composition containing an organic polyisocyanate compound.